HK1021693B - Device for the extraction of sealed flexible bags - Google Patents

Description

The invention relates to a device for the implementation of a process of extraction of closed flexible bags containing at least one substance for the preparation of a beverage, the bag being made up of two thin flexible sheets of the same material, welded on their periphery and substantially symmetrical to each other with respect to the weld plane, the said substance being either powdery or compacted into a wafer of suitable shape in one or more pieces.

The use of pre-packaged and pre-packaged portions of ground coffee for the preparation of espresso-type coffee has the advantage of facilitating coffee preparation operations while ensuring a relative consistency in product quality.

These portions are currently available in two main forms.

In a first general form, the portions described in CH 636'311, US 5'012'629 and EPA 0'272'432 consist of two sheets of filter paper welded on their periphery and filled with ground coffee. This solution has the disadvantage of requiring a tight overpackage to prevent the product from oxidizing during storage. This overpackage is an additional cost and an additional operation on the part of the consumer who must dispose of it before the desired coffee is extracted.

Patents FR 1410288 and US 3007392 relate to devices for extracting portions with overpackaging as mentioned above.

In a second form, described in application PCT/CH91/00'222, the portion consists of a watertight capsule with a concave bottom opening in its extraction device by deformation by the introduction of the extraction fluid and then punching against the tips. This capsule, consisting of a sealed envelope forming a sidewall and two walls, one of which is the bottom of the cartridge and the other the opposite end of the cartridge, has the disadvantage of using several different packaging materials simultaneously, at least one of which must be sufficiently thick to achieve a semi-rigidity. It can only be used in a single direction with a tight extraction arrangement as it is not suitable for the volume of the capsule, as it is not more compact.

The object of the present invention is to propose a device for extracting a closed flexible pouch without opening it, without requiring any special positioning of the upper and lower sides of the pouch.

The invention relates to a device for the implementation of a process in which the bag is placed and clamped in its extraction device consisting of a closed chamber and a bag holder, a mixture of air and water is introduced into the bag at a pressure of between 2 and 20 bar by means of a guide organ in such a way as to progressively and locally stretch the extraction face of the bag against a relief surface of the bag containing relief and hollow elements, the said extraction face tearing into multiple places in a path predetermined by the location of the relief elements and/or its hollow opening by reaching the rupture tension, to allow the liquid to be extracted after the rupture.

The process is also characterized by the high value of the extraction pressure, since its maximum value is not necessarily reached when the bag is opened, but may be later during extraction, when the load loss through the coffee bed has reached its maximum.

The process will be better understood by describing its successive phases, which can be carried out, in the particular case of its use for coffee, from espresso machines of the seller which have the means, from the moment of construction or by the addition of adaptors, to puncture one of the sides of the bag, introduce water into it, tear the other side in a controlled manner as a result of its deformation under pressure and collect the coffee extract. The bag is first placed in the bag holder, the lower face in this arrangement becoming the extraction face. The bag holder with the bag is then placed in the machine, the upper face of the bag is then perforated by the sharp or perforating element (s) placed under the lower face of the upper part of the extraction cavity.

During this step, the shape of the bag can be voluntarily changed from its original shape by adapting to the configuration of the cavity of the extraction device, so that the shape of the bag is perfectly defined before extraction, when it is set up, even after it has undergone possible deformation as a result of previous handling, especially when the bag contains a product that is not very compacted or even not compacted.

According to one variant of the process, the setting-up operation involves a tightening effect which reduces the available internal volume of the bag in order to limit to a defined minimum the areas not filled with the substance to be extracted. Indeed, depending on the manufacturing method of the bag, its initial volume may be higher than that of the substance contained, if it is desired that the substance be slightly compacted before extraction, as is the case with ground coffee. This adjustment of the volume makes it possible to facilitate extraction, since the substance is regularly placed in the cavity, it is properly passed through the extraction fluid and, moreover, when the bag is evacuated, it is not filled with excess water, which favors the practicality and cleanliness of the process.

In addition, the soft top of the bag can, under the influence of water pressure and the swelling of the coffee, come to rest against the top of the chamber, thus improving the wetting of the coffee and therefore the quality of its extraction. In another variant of the process, auxiliary means provided under the upper face of the extraction device and/or on the lower face of the said device allow the coffee to be moved from the bag to specific and preferred areas in order to promote the quality of extraction by avoiding dead zones.

In order to regularise the extraction of a bed of substance, it is desirable that the bed be neither too thin nor uneven in thickness, although with a flexible bag these defects could be observed if the above methods were not used.

In a variant of bags containing coffee compacted during production, the volume of the cavity corresponds more closely to the size of the bag and the bag to avoid free zones between the bag and the bag and untimely preferential routes during extraction. The surface of the bag is placed against the walls of the extraction cavity, the extraction face being deformed locally by gradually stretching under the pressure of the relief elements of the bag holder in the infusion drain holes. This essential phase ensures a pre-squeezing time for the coffee before extraction.

Air may be the air in the pipes of the said machine which mixes with the water when the extraction process is started.

Under certain conditions, depending on the espresso machines used and the initial heating temperature, the first water fractions may appear as steam.

In a variant of the procedure, a rest time, with the injection of the extraction fluid stopped between the third and fourth steps, may be observed. The material which constitutes the surface of the extraction, when it reaches its breaking stress as a result of stretching, tears begin to form at the point of the protruding parts of the relief or in the hollow parts formed between the above-mentioned parts in relief. Depending on the shape of the relief, the tears may also extend in the two areas mentioned above. The parts thus fractured without breaking away from the surface of the extraction released from its tension are then applied precisely against the relief with the effect of enlarging the openings made,The internal pressure of the bag drops partially, but this momentary decompression is limited because the flow of fluid escaping from the bag is laminated by both the small gaps formed by the lips of the torn material of the extraction face supporting the relief and by the flow holes in or near the relief. The flow is perfectly controlled, thus excluding any untimely displacement of the solid phase of the contents of the bag which could obstruct the flow holes and subsequently obstruct the regularity and reproducibility of the process of extraction.

According to the terminology used in patent CH 668'545 for a pre-weakened operculum capsule, this opening phase of the bag can be considered as an aeration phase of the powdered material.

In a variant of the procedure, a rest time, with the injection of the extraction fluid stopped between the fourth and fifth batches, may be observed. In a fifth step, the coffee is extracted under a pressure of 2 to 20 bar, this pressure being voluntarily and essentially linked to the loss of load through the wet coffee bed and thereby compacted.

Additional openings of the extraction face may be produced, if necessary, by the relief parts of the drop-height baggage compartment preferably in its peripheral zone when the extraction pressure reaches high values. In a sixth step, the bag holder is released and the bag is evacuated, for example by simply turning the bag holder.

In a variant of the jaw-dropping system described below, the bag is ejected manually by means of an insert or automatically in a suitable container at the end of the fifth period.

According to a first variant of the process, tears are produced in the central part of the cavities (holes) formed between the protruding parts of a relief element when the material reaches its breaking tension at the point of its deformation.

A second method is that the rupture of the extraction face of the bag may be initiated at the level of the raised elements and then extended into the centre of the cavities (holes) formed by the raised elements.

A third variant of the process is to open the extraction face by applying the breakdown voltage to the location of relief elements possibly combined with complementary elements, which are not intended to tear the extraction face of the bag but to promote flow, while ensuring the cleanliness of the system.

The coffee extract is able to pass between the torn and deformed parts of the extraction face of the bag to the flow holes, because these torn parts cannot be completely sealed against the ground because of a certain relative rigidity due to their relatively small dimensions.

The number of tears in the extraction face is preferably several dozen; the geometry of the relief elements is generally arranged in such a way that the teared parts do not completely detach but remain united in the bag.

The description given below as an example of application to roasted and ground coffee is not limited, as the process is applicable to other products or mixtures of products contained in a flexible pouch such as tea, soluble coffee, a mixture of ground and soluble coffee, a chocolate product or a dehydrated food and intended for the preparation of beverages or foodstuffs in the form of infusions.

Err1:Expecting ',' delimiter: line 1 column 275 (char 274)

The inner diameter of the bag is preferably between 25 and 70 mm and the welded edge is 3 to 15 mm wide. When filled, the bag has a thickness in the centre, preferably between 5 and 20 mm. In the case of coffee, the dose contained may vary between 5 and 20 g of ground coffee, whether or not compacted into a crust. The general shape of the bag is circular, oval or polygonal with 4 to 10 sides with possibly rounded edges, or may be a combination of the three.

The extraction face of the bag after it has been placed in the machine need not be in a horizontal plane; other orientations may be preferred for the convenience of the processes.

Instead of placing the bag in the bag holder which is then placed in the machine, a device may be envisaged in which the bag holder is an integral part of the machine in a system called a jaw, the bag being inserted directly into the machine and the top of the bag being perforated by sharp or piercing elements when the jaw is closed.

In this case, the device of the invention includes: a top with means for piercing the top of the bag and allowing the introduction of water into the bag and a locking lever,a bottom with a housing for housing the capsule and hollow and raised elements, in which the bag can be inserted directly into the device, the top or the bottom has either a horizontal or vertical rotation, a folding or a drawing movement to allow it to be inserted, in which the locking lever is in solidarity with the upper and lower parts when the bag is removed, and in which the extraction face of the bag is gradually and locally stretched against the raised and hollow elements, the extraction face being torn into multiple places along a line determined by the location of the raised and hollow elements and reaching its break-up tension there, to allow the liquid to flow after extraction.

The advantage of this is that when the bag is tightened or loosened, there is no rotational movement of the bag, which avoids the use of showers or rotating pyramids.

Another advantage is that the clamping force before extraction can be increased by means of a demultiplier mechanism, which also allows for automatic ejection of the bag after extraction into a special container.

This arrangement also allows the introduction of water and the extraction of coffee on the same side of the bag, the water introduction organ (s) and the relief elements being preferably concentric, one in the centre and the other at the periphery.

In a simplified version, the bag is removed using a cup that is either integral or not part of the bag holder. This cup may, for example, be of a ring shape and fit around the part containing the embossed elements. It may be moved by a spring for the ejection of the bag or be removed manually from the bottom part. In the absence of this cup, the use of a bag from a side-tongue is particularly advantageous.

It is obvious to the man of the trade that the various variants described above can be adapted to be incorporated into an automated mechanical device which, by known secondary means, which will not be described in detail, ensures the positioning of the bag, its tightness, and then, after infusion, the loosening and release of the used bag.

According to a first variant of the water-inlet device, the means of the upper part to puncture the upper side of the bag and introduce water into the bag may be in the form of a water distribution grid with elements such as protruding tips, blades or crosses on its lower side, for example those described in European patent application 91'111'211.8 filed on 5 July 1991.

A second variant may be one or more water injection needles, protruding in the cavity of the upper part, for example of the type described in European patent application 90-114'402.2 filed on 27 July 1990.

The water-inlet needle (s) are designed in a tapered shape, so that they pierce the bag material through openings which can be closed at least partially, in order to minimise the discharge when the bag is removed. They also do not prevent the bag from swelling and closing against the adjacent wall. Finally, the size and arrangement of these water-inlet organs are chosen so as not to create untimely preferential pathways in the coffee bed, but rather to irrigate it regularly throughout its volume. The shape, size and arrangement of the bag or needles are adapted to the shape and size of the bag.

In the case of a layout with several water-inlet needles, it may be advantageous to mount these needles on a part capable of rotational movement in order not to tear the bag, this movement being then synchronised by drive when the bag holder is inserted.

The relief elements which open the extraction face of the bag are of the same nature as the five types described in European patent application 92'107'548.7 filed on 5 May 1992.

In the first form, the relief elements consist of small straight or slightly sinuous or arch-shaped sticks, closed or not, of distinct lengths and arranged radially, concentrically, parallel or perpendicularly on a grid punched with many small holes.

In a second form of construction, the relief elements can also be presented as small prisms, pyramidal trunks, cylinders or cone trunks of polygonal, circular or otherwise section.

In a third embodiment, the embossed elements form at their base circular or ovoid cavities at the bottom of which are the coffee-flow holes.

In one of the three forms described above, the embossed elements are a piece in their own right arranged on a flow grid.

Another variant is that the embossed elements may be part of a plate through the filtration orifices for the flow of the extract.

In a fourth unrepresented embodiment, the relative arrangement of the relief elements and the flow holes is reversed. The relief element consists of a piece with parts hollow relative to its main surface and flow holes practiced at least in the protruding part.

In a fifth embodiment, the embossed elements are pyramidal pieces combined with complementary elements, which are not intended to tear the extraction face of the cartridge, but to facilitate the flow of the extracted fluid while retaining the substance, for example in the form of terraces 0.2 to 1 mm wide surrounding the pyramidal shapes and channels at the base, about 0.7 to 2.5 mm wide and about 0.3 to 1.8 mm deep. These channels are pierced by numerous flow openings, calibrated to a diameter of a few tenths of a millimeter.

In the first variant, pyramidal shapes consist of truncated pyramids 1 to 7 mm on a side and 1 to 7 mm high, preferably arranged according to a grid with a step usually between 3 and 10 mm. The faces have a preferential angle of 10 to 30° with the vertical.

The upper side of the pyramids serves as a support surface when the bag is subjected to pressure.

In a second variant, pyramidal shapes are made up of pyramids, whole and/or partial, i.e. asymmetric. Asymmetric pyramids can be obtained either with pyramids whose vertical faces do not all have the same angle or with pyramids that were originally symmetrical but whose vertical portions have been removed.

For this fifth embodiment, the faces of the relief elements and possibly of terraces and channels may have small grooves (channels) which facilitate the drainage of the extract, the material of the extraction face being sufficiently rigid to not allow it to completely match the shape of the groove.

Several types of pyramids can coexist in this fifth form of realization.

In a sixth preferred embodiment, the height of the pyramids and adjacent channels is not constant over the entire surface. Part of this is intended to cause the bag to open only when a higher pressure than the usual value is reached, thus correcting the extraction flow rate by increasing it. This effect is preferably achieved by decreasing the height of the pyramids and increasing the depth of the channels separating the terraces.

In a variant of the above forms, extraction may be limited to a preferentially ringed area of the lower face, in order to force water to travel a maximum path into the coffee bed when the water introduction is central.

In all the cases described above, the openings in the lower wall of the bag are the result of deformation to rupture, but only under and after pressure by water or the extraction water-air mixture.

It is understood that everything described above in relation to the device of the invention, which concerns the relief elements, the drainage chamber, the baggage compartment sealing device, also applies to the baggage compartment without the need to repeat the description.

In particular, the bag holder may be in one or two parts with a lower part receiving the bag and supporting that part, that lower part comprising raised and hollow elements and flow openings to allow the liquid to flow.

The following description is made by reference to the drawings, figures 1 to 10 being merely useful for understanding the invention, on which: Fig. 1 is a schematic representation of a closed flexible bag extraction device,Fig. 1a is a magnified view of part A of Fig. 1,Fig. 2 is a split cut view of the upper part for water injection of the said device,Fig. 3 is a plan view of the various water injection points of Fig. 2,Fig. 4 is a partial schematic representation of a closed flexible bag extraction device,Fig. 5 is a schematic representation of the upper part for water injection,Fig. 6 is a partial view in plan of the lower part consisting of raised and hollow elements and flow openings,Fig. 7 is a cut according to line 6-6 of Fig. 6,Fig. 8 is a schematic representation of the positioning of the water intake organs provided for under the upper face of the device and the raised elements provided on the lower face for the flow of the coffee extract,Fig. 9 is a schematic representation of the positioning of the water intake organs provided for under the upper face of the device and the elements provided on the lower face for the flow of the coffee extract,Fig. 10 is a schematic representation of the positioning of the water intake and coffee extraction organs, all of which are shown on the lower face of the device,Fig. 11 is a schematic representation in perspective of a closed flexible bag extraction system, according to the invention andFig. 12 is a schematic representation of the upper part of the extraction system according to Fig. 11.

As shown in Fig. 1, the bag (1) is placed on the lower part (2) which together with its support (4) forms the bag holder.

The upper part (8) has a water inlet (10) and points (11) to pierce the upper side of the bag (1). The lower part (2) has protruding elements (19) and drain holes (20).

The operation is as follows: the bag (1) is placed on the lower part (2) and the support assembly (4), the lower part (2) and the bag (1) are held by the handle (22) and the clamping legs (3) are attached to the clamping ramps (7) of the upper part (8).

The inner lower conical edge (23) of the upper part cooperates with the conical edge (24) of the lower part by pinching the periphery of the bag (1). The tips (11) pierce the bag (1) and the hot water comes through the water intake channel (10) and enters the bag (1). The pressure in the bag increases and the lower side of the bag will flatten against the protruding elements (19) until it tears against the said protruding elements by reaching its breaking tension. The extraction phase begins.

Figures 2 and 3 show a different upper part for the water intake than Figure 1. This part is in two parts: the part (41) with a central water intake (42) and a distribution grid (43) with points (44) to pierce the upper side of the bag to be extracted, the said disc being intended to fit into the housing (45) of the part (41). The groove (46) of the disc (43) is partially occupied by the points (44), allowing the water to pass through to the bag to be extracted. The disc (43) rotates in its housing (45); it is held in place by a screw (48) in the disc's arrangement (47)

An o-ring seal (49) is provided and several water intake channels (50) are arranged on the periphery of the part (41) so that when the water is removed, it pushes the seal downwards and thus ensures the watertightness of the system.

As shown in Fig. 4, the extraction device consists of an upper part (12) with injection needles (13) placed under the vault of the cavity. When the injection needles are tightened, they pierce the upper side of the bag, allowing the extraction fluid to be introduced through the channel (25). This upper part has a protruding (14) conical-looking element which fits into a complementary cone (26) in the lower part (15). By being fitted into each other when the parts are tightened, these elements help to tighten the faces of the bag and recast the powdery substance.

The lower chamber also has protruding elements (17) and flow openings (18) for the coffee to flow through.

Fig. 4 does not represent the leg and clamp hold system. The extraction method is the same as for the device in Fig. 1.

Fig. 5 shows another way of making the upper part of the water injection (51) with a water inlet (52) and a single point (53) to pierce the bag, this point including a vent (54) to bring the water into the bag. This part (51) includes a concave zone (55) to allow better distribution of the water, so that the upper side of the bag is plated against the concave zone.

Fig. 6 shows that there are different types of pyramidal elements in relief: pyramidal trunks (29), pyramids (30) truncated on 2 sides, asymmetric pyramids (31), symmetric pyramids (32), pyramids (33) with undulations, pyramids (34) truncated on 3 sides and pyramids (40) truncated on 4 sides.

The flow orifices (36) can be of three different shapes: cylindrical (37), downward-draining (38) or cylindrical and downward-draining (39).

The presence of terraces (35) allows the opening (or tearing) of the bottom of the bag to be controlled, thus providing a filter function.

Figure 8 shows the puncture organs (57) of the bag (58) and the raised and hollow elements (59) arranged around the flow openings (60).

Fig. 9 shows the extraction of a bag (58) with a single tip (61) and raised and hollow elements (62) and flow holes (63) arranged on the periphery of the bag.

Finally, Fig. 10 shows a single point (64) of upward water flow and the coffee recovery system on the same side with raised and hollow elements (65) around the flow openings (66).

Figures 11 and 12 show an extraction system consisting of a chassis (70) on which a top part (75) is mounted rotating along the shaft (71) and which itself contains a locking lever (72) with hooks (73) mounted on an arm (83) which is mounted rotating along the shaft (74). The top part (75) closes on a bottom part (76) mounted rotating along the shaft (77) and which has a housing (78) with hollow and raised elements (79) designed to receive the bag to be extracted.

The operation is as follows: the bag is placed in the housing (78), the top (75) is lowered by pressing the locking lever (72) until the hooks (73) are attached to the rod (77).

An eccentric (80) allows the upper water intake (81) to be tightly pressed against the lower part (76) to ensure a good system seal by pressing the joint well (82). The bag is removed and the locking lever (72) is released to lift the upper part (75).

Claims (12)

1. Device for extraction of sealed flexible sachets, comprising:

   - an.upper member or arm (75) provided with means which are designed to perforate the upper surface of the sachet (1) and permit introduction of water into the said sachet, and with a locking lever (72);

   - a lower member (76) which has a receptacle (78) for accommodation of the capsule and of the raised and hollow portions (79),

   wherein the sachet can be inserted directly in the said device, the upper member or the lower member has either a movement of rotation according to a vertical or horizontal axis, or a movement of tilting, or a sliding movement which permits this insertion,

   - wherein the locking lever renders the upper member and the lower member integral at the moment of extraction of the sachet; and

   - wherein the extraction surface of the sachet is drawn progressively and locally against the raised and hollow portions, the said extraction surface tearing in multiple locations according to a path which is predetermined by the location of the said raised and hollow portions and reaching its rupture tension there, in order to permit flow of the liquid after extraction.
2. Device according to claim 1, characterised in that the upper member (75) rotates according to a horizontal axis (71).
3. Device according to claim 1 or claim 2, characterised in that the locking lever (72) has a system of hooks (73) which engages on the rod (77) of the lower member (76) at the moment of extraction of the sachet.
4. Device according to any one of claims 1 to 3, characterised in that the locking lever (72) is fitted such as to rotate along the rod (74).
5. Device according to any one of claims 1 to 4, characterised in that the locking lever comprises a cam (80) in order to clamp the upper member (75) well against the lower member (76) during extraction of the sachet.
6. Device according to claim 5, characterised in that the cam (80) supports the upper member for intake of water (81), against the seal (82).
7. Device according to any one of claims 1 to 6, characterised in that the lower member (76) comprises means which permit ejection of the sachet when extraction is completed.
8. Device according to any one of claims 1 to 7, characterised in that the means which are designed to perforate the upper surface of the sachet are in the form of a disc (43) provided on its lower surface with elements such as points (44), blades or a projecting cross.
9. Device according to any one of claims 1 to 7, characterised in that the means which are designed to perforate the upper surface of the sachet are one or a plurality of points (11) for injection of water, disposed such as to project in the cavity of the upper member.
10. Sachet holder which can be used in the device according to any one of claims 1 to 9, characterised in that it comprises a lower member (2, 76) which receives the sachet and the support (4) for this member, the said lower member comprising raised and hollow portions (19, 79) and flow apertures (18, 37, 38, 39) in order to permit flow of the liquid.
11. Sachet holder according to claim 10, characterised in that the raised and hollow portions are in the form of pyramids.
12. Sachet holder according to claim 10 or claim 11, characterised in that the lower member has corrugations on its periphery.